1. Field of Invention
The present invention relates to a twist vehicle, and more particularly to a twist vehicle having a rear operation system, wherein the steering unit of the twist vehicle is mounted in a relatively rear position with respect to vehicle frame of the twist vehicle.
2. Description of Related Arts
As shown in FIG. 1 of the drawings, a conventional twist vehicle comprises a vehicle frame 1, a pair of rear wheels 11 rotatably mounted on two sides of rear portion of vehicle frame 1 to support the twist vehicle, a pivot 13, a twisting unit 14 having two driving wheels space apart from each other and from the pivot 13, and a handle 15 connected to the twisting unit 14. The twisting unit 14 is pivotally connected to the vehicle frame 1 about the pivot 13. To operate the conventional twist vehicle, a rider has to impart clockwise and anti-clockwise movements subsequently to the handle 15, thus to make the twisting unit 14 to rotate and then the pair of driving wheels 12 to turn accordingly about the pivot 13. Amid a series of such turning motions of the driving wheels 12, the twist vehicle moves forwardly.
Since the pair of driving wheels are turned about the pivot 13, so, the longer the perpendicular distance between the pivot 13 and the handle 15, the less the force a rider has to apply to the handle 15 for the same turning moment. However, the longer the perpendicular distance between the pivot 13 and the handle 15, the less comfort the rider should feel as the rider must lean forward to turn the handle 15. Therefore, this kind of conventional twist vehicle is undesirable from the viewpoint of ergonomics.
Thereafter, the conventional twist vehicle is improved as shown in FIG. 2. A more recent twist vehicle comprises a vehicle frame 1, a pair of rear wheels 11 for supporting the vehicle frame 1, a steering unit 15, a transmission unit 150 and a triangular twisting unit 120 having one end portion connected to the transmission unit 150 and remaining two end portions connected to a pair of driving wheels 12 respectively. The transmission unit 150 is rotatably and perpendicularly connected to the vehicle frame 1. When clockwise and anti-clockwise movements are subsequently imparted to the steering unit 15, the transmission unit 150 and therefore the twisting unit 120 turn accordingly as a result, causing the twist vehicle to move forwardly. The steering unit 15 of this kind of more recent twist vehicle extended upwardly and perpendicularly with respect to the vehicle frame 1, rather than frontwardly as shown in FIG. 1, thus preventing a rider from leaning forwardly. However, since the twisting unit 120 is directly connected to the transmission unit 150 which is connected to the steering unit 15, therefore, the more backward the steering unit is positioned with respect to the vehicle frame, the shorter the distance between the axle of the pair of driving wheels 12 and axle of the pair of rear wheels 11, and hence the easier the twist vehicle to flip over.
A main object of the present invention is to provide a twist vehicle which comprises a rear operation system wherein the steering unit of the twist vehicle can be mounted at a relatively backward position such that a rider is able to operate the twist vehicle comfortably, without affecting the axle distance between the pair of driving wheels and the pair of rear wheels of the twist vehicle.
Another object of the present invention is to provide a twist vehicle which comprises a rear operation system wherein the steering unit of the twist vehicle can be mounted inclinedly with respect to the vehicle frame such that a rider is able to operate the twist vehicle comfortably, without affecting the axle distance between the pair of driving wheels and the pair of rear wheels of the twist vehicle.
Another object of the present invention is to provide a twist vehicle which comprises a rear operation system which comprises a driven member which is connected to twisting unit of the twisting vehicle, a driving member which is connected to steering unit of the twist vehicle and is backwardly apart from the driven member with respect to vehicle frame of the twist vehicle, and an endless transmission member, wherein the driven member and the driving member are mechanically connected by the endless transmission member belt, such that any rotating motions of the driving member can be transferred to the driven member by the endless transmission member.
To enable further understanding of the objects and the underlying technological method, the brief description of the drawing below is followed by a detailed description of a preferred embodiment.